+/* Opens a non-blocking IPv4 socket of the specified 'style' and connects to
+ * 'target', which should be a string in the format "<host>[:<port>]". <host>
+ * is required. If 'default_port' is nonzero then <port> is optional and
+ * defaults to 'default_port'.
+ *
+ * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
+ *
+ * On success, returns 0 (indicating connection complete) or EAGAIN (indicating
+ * connection in progress), in which case the new file descriptor is stored
+ * into '*fdp'. On failure, returns a positive errno value other than EAGAIN
+ * and stores -1 into '*fdp'.
+ *
+ * If 'sinp' is non-null, then on success the target address is stored into
+ * '*sinp'. */
+int
+inet_open_active(int style, const char *target_, uint16_t default_port,
+ struct sockaddr_in *sinp, int *fdp)
+{
+ char *target = xstrdup(target_);
+ char *save_ptr = NULL;
+ const char *host_name;
+ const char *port_string;
+ struct sockaddr_in sin;
+ int fd = -1;
+ int error;
+
+ /* Defaults. */
+ memset(&sin, 0, sizeof sin);
+ sin.sin_family = AF_INET;
+ sin.sin_port = htons(default_port);
+
+ /* Tokenize. */
+ host_name = strtok_r(target, ":", &save_ptr);
+ port_string = strtok_r(NULL, ":", &save_ptr);
+ if (!host_name) {
+ ovs_error(0, "%s: bad peer name format", target_);
+ error = EAFNOSUPPORT;
+ goto exit;
+ }
+
+ /* Look up IP, port. */
+ error = lookup_ip(host_name, &sin.sin_addr);
+ if (error) {
+ goto exit;
+ }
+ if (port_string && atoi(port_string)) {
+ sin.sin_port = htons(atoi(port_string));
+ } else if (!default_port) {
+ VLOG_ERR("%s: port number must be specified", target_);
+ error = EAFNOSUPPORT;
+ goto exit;
+ }
+
+ /* Create non-blocking socket. */
+ fd = socket(AF_INET, style, 0);
+ if (fd < 0) {
+ VLOG_ERR("%s: socket: %s", target_, strerror(errno));
+ error = errno;
+ goto exit;
+ }
+ error = set_nonblocking(fd);
+ if (error) {
+ goto exit_close;
+ }
+
+ /* Connect. */
+ error = connect(fd, (struct sockaddr *) &sin, sizeof sin) == 0 ? 0 : errno;
+ if (error == EINPROGRESS) {
+ error = EAGAIN;
+ } else if (error && error != EAGAIN) {
+ goto exit_close;
+ }
+
+ /* Success: error is 0 or EAGAIN. */
+ goto exit;
+
+exit_close:
+ close(fd);
+exit:
+ if (!error || error == EAGAIN) {
+ if (sinp) {
+ *sinp = sin;
+ }
+ *fdp = fd;
+ } else {
+ *fdp = -1;
+ }
+ free(target);
+ return error;
+}
+
+/* Opens a non-blocking IPv4 socket of the specified 'style', binds to
+ * 'target', and listens for incoming connections. 'target' should be a string
+ * in the format "[<port>][:<ip>]". <port> may be omitted if 'default_port' is
+ * nonzero, in which case it defaults to 'default_port'. If <ip> is omitted it
+ * defaults to the wildcard IP address.
+ *
+ * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
+ *
+ * For TCP, the socket will have SO_REUSEADDR turned on.
+ *
+ * On success, returns a non-negative file descriptor. On failure, returns a
+ * negative errno value. */
+int
+inet_open_passive(int style, const char *target_, uint16_t default_port)
+{
+ char *target = xstrdup(target_);
+ char *string_ptr = target;
+ struct sockaddr_in sin;
+ const char *host_name;
+ const char *port_string;
+ int fd, error;
+ unsigned int yes = 1;
+
+ /* Address defaults. */
+ memset(&sin, 0, sizeof sin);
+ sin.sin_family = AF_INET;
+ sin.sin_addr.s_addr = htonl(INADDR_ANY);
+ sin.sin_port = htons(default_port);
+
+ /* Parse optional port number. */
+ port_string = strsep(&string_ptr, ":");
+ if (port_string && atoi(port_string)) {
+ sin.sin_port = htons(atoi(port_string));
+ } else if (!default_port) {
+ VLOG_ERR("%s: port number must be specified", target_);
+ error = EAFNOSUPPORT;
+ goto exit;
+ }
+
+ /* Parse optional bind IP. */
+ host_name = strsep(&string_ptr, ":");
+ if (host_name && host_name[0]) {
+ error = lookup_ip(host_name, &sin.sin_addr);
+ if (error) {
+ goto exit;
+ }
+ }
+
+ /* Create non-blocking socket, set SO_REUSEADDR. */
+ fd = socket(AF_INET, style, 0);
+ if (fd < 0) {
+ error = errno;
+ VLOG_ERR("%s: socket: %s", target_, strerror(error));
+ goto exit;
+ }
+ error = set_nonblocking(fd);
+ if (error) {
+ goto exit_close;
+ }
+ if (style == SOCK_STREAM
+ && setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes) < 0) {
+ error = errno;
+ VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s", target_, strerror(error));
+ goto exit_close;
+ }
+
+ /* Bind. */
+ if (bind(fd, (struct sockaddr *) &sin, sizeof sin) < 0) {
+ error = errno;
+ VLOG_ERR("%s: bind: %s", target_, strerror(error));
+ goto exit_close;
+ }
+
+ /* Listen. */
+ if (listen(fd, 10) < 0) {
+ error = errno;
+ VLOG_ERR("%s: listen: %s", target_, strerror(error));
+ goto exit_close;
+ }
+ error = 0;
+ goto exit;
+
+exit_close:
+ close(fd);
+exit:
+ free(target);
+ return error ? -error : fd;
+}
+
+/* Returns a readable and writable fd for /dev/null, if successful, otherwise
+ * a negative errno value. The caller must not close the returned fd (because
+ * the same fd will be handed out to subsequent callers). */
+int
+get_null_fd(void)
+{
+ static int null_fd = -1;
+ if (null_fd < 0) {
+ null_fd = open("/dev/null", O_RDWR);
+ if (null_fd < 0) {
+ int error = errno;
+ VLOG_ERR("could not open /dev/null: %s", strerror(error));
+ return -error;
+ }
+ }
+ return null_fd;
+}
+